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The Wolff–Chaikoff effect [1] is a presumed reduction in thyroid hormone levels caused by ingestion of a large amount of iodine. [ 2 ] It was discovered by Drs. Jan Wolff and Israel Lyon Chaikoff at the University of California, Berkeley : in 1948, they reported that injection of iodine in rats almost completely inhibited organification ...
[8] [9] Hashimoto's thyroiditis is the most common cause of hypothyroidism in countries with sufficient dietary iodine. [3] Less common causes include previous treatment with radioactive iodine , injury to the hypothalamus or the anterior pituitary gland, certain medications, a lack of a functioning thyroid at birth , or previous thyroid surgery .
Unlike the Wolff–Chaikoff effect, the Plummer effect does not prevent the thyroid from taking up radioactive iodine, e.g. in the case of nuclear emergencies.Therefore, "plummering" with high-dose iodine is only effective in a short time window after the release of radionuclides. [9]
Hashimoto's thyroiditis, also known as chronic lymphocytic thyroiditis, Hashimoto's disease and autoimmune thyroiditis, is an autoimmune disease in which the thyroid gland is gradually destroyed. [7] [1] Early on, symptoms may not be noticed. [3] Over time, the thyroid may enlarge, forming a painless goiter. [3]
[28] [29] Hyperthyroidism is the effect of iodine being a substrate of thyroid hormones, and is then called the Jod-Basedow phenomenon. The risk is higher in those with an underlying thyroid disease, such as toxic multinodular goiter, Graves' disease, or Hashimoto's thyroiditis, where thyroid monitoring is indicated. [30]
The gamma-emitting isotopes iodine-123 (half-life 13 hours), and (less commonly) the longer-lived and less energetic iodine-125 (half-life 59 days) are used as nuclear imaging tracers to evaluate the anatomic and physiologic function of the thyroid. Abnormal results may be caused by disorders such as Graves' disease or Hashimoto's thyroiditis.
In some ways the Jod-Basedow phenomenon is the opposite of two physiological compensation mechanisms, the Plummer effect and the Wolff–Chaikoff effect, which in normal persons and in persons with thyroid disease, suppress the thyroid hormone after ingestion of large quantities of iodine or iodide. However, unlike the Plummer and Wolff ...
In areas where iodine-deficiency is not found, the most common type of hypothyroidism is an autoimmune subtype called Hashimoto's thyroiditis, with a prevalence of 1-2%. [40] As for hyperthyroidism, Graves' disease , another autoimmune condition, is the most common type with a prevalence of 0.5% in males and 3% in females. [ 41 ]